Abstract

Moderate pressure techniques have been used to prepare pyrochlore-like materials. The compound has been characterized by neutronpowderdiffraction, magnetic, magnetotransport, and Hall measurements. This material is ferromagnetic below Both electrical resistance and magnetoresistance(MR) are enhanced with respect to stoichiometric due to the drastic reduction in the number of carriers (electrons) induced by hole doping. MR(0.5 T) is higher than at 120 K, and MR(9 T) is 30% at room temperature. We show that hole doped derivatives of are promising candidates in which to search for large bulk magnetoresistance.